Device for filling containers

ABSTRACT

The invention relates to a device for filling containers, comprising an arrangement ( 7 ) for feeding filling material to at least one dosing system ( 5 ) forming a flow path ( 27 ) containing a dosing valve ( 29 ) that can be opened at least for the duration of the dosing processes, in order to distribute the dosing amounts of the filling material via at least one filling line ( 9 ), into relevant containers. Said device is characterised in that the dosing system ( 5 ) comprises an element ( 31, 33, 43 ) that is disposed in the flow path ( 27 ) downstream of the dosing valve ( 29 ), for selectively producing a suction effect in the flow path ( 27 ), and a control mechanism ( 39 ) that activates the element ( 31, 33, 43 ) producing the suction effect, according to dosing processes respectively completed by closing the dosing valve ( 29 ).

The invention relates to a device for filling containers, comprising anarrangement for feeding filling material to at least one dosing systemwhich forms a flow path in which there is a dosing valve which can beopened at least for the duration of the dosing processes in order todeliver the dosing amounts of the filling material to the pertinentcontainers by way of at least one filling line.

In the pertinent prior art, a system which economically enablesautomated molding (blow molding or vacuum molding), filling, and sealingof containers is known under the trademark bottelpack®. When theindicated containers are to be filled with sensitive products, forexample, pharmaceuticals, on the one hand the international standardsfor aseptic packaging must be satisfied, and on the other hand it mustbe ensured that during each filling process a specific dosing amount isfilled in, and the quantity of the filling amount must be maintainedwith the greatest precision, especially when highly efficaciouspharmaceuticals are involved.

To meet these requirements, in a device of the initially named typewhich is disclosed in document EP 0 418 080 B1, for each filling linewhich is assigned to a pertinent container to be filled, there is adosing valve which opens and closes in a time-controlled manner by meansof electromagnetic actuation, the opening time for each dosing processbeing chosen such that at a set buffer pressure of the filling materialwhich is available in a dosing distributor, the desired dosing amountflows through the dosing valve during the opening time.

Based on this prior art, the object of the invention is to makeavailable a device of the aforementioned type which is characterized byincreased dosing accuracy compared to the prior art.

This object is achieved according to the invention by a device which hasthe features of claim 1 in its entirety.

Accordingly, one essential feature of the invention consists in thatdownstream of the dosing valve there is a controllable means by which asuction action can be produced on the flow path when the respectivedosing processes are completed, specifically when the pertinent dosingvalve closes. When the dosing process is ended, in the filling line thisyields a suction action which causes return suction of the remainingliquid out of the filling line or at least prevents dripping of liquidafterwards. A maximum of dosing accuracy certainly can be achieved inthis way.

In advantageous exemplary embodiments, between the dosing valve and thefilling line there is a choke site, which constricts the flow pathduring the dosing processes, in the region of the choke site there beinga movable control element which defines the width of the flow pathdepending on its position setting and which can be transferred into aposition which widens the flow path at the choke site by forming abypass when the means which produces the suction action is activated.The choke site, which in interaction with the time control of theopening time of the dosing valve determines the dosing amount, ininteraction with the control element which defines the width of the flowpath also forms a part of the means which produces the suction actionand whose operating principle consists in that the movable controlelement forms a widening in the flow path as a bypass of the choke site,resulting in an enlargement of the inside volume of the flow path andthus an afterflow effect.

The arrangement in this connection can be advantageously made such thatthe means which produces the suction action is formed by a bypass valvedesigned as a diaphragm valve whose diaphragm which forms the movablecontrol element with its one closing side delimits the flow path at thechoke site and on whose other control side a negative pressure can beapplied for producing a suction action in order to cause the diaphragmto execute a deflection motion which widens the flow path and whose liftproduces the suction action on the filling line. In these exemplaryembodiments the means which produces the suction action is characterizedby an especially simple construction.

The dosing valve can also be formed by a diaphragm valve in acorrespondingly advantageous manner.

An especially compact and simple structure of the dosing system can beachieved when the dosing valve and downstream bypass valve are diaphragmvalves which are controlled by a joint diaphragm extending along theflow path.

In order to support the movement of the diaphragm both at the dosingvalve and at the bypass valve into the rest position, i.e., into therespective closed position, and to elicit deflection movements out ofthe rest position, on the control side of the diaphragm opposite theclosing side alternately an overpressure as the closing pressure and anunderpressure as the opening pressure can be applied to the pertinentdosing valve and to the pertinent bypass valve by way of assignedcontrol lines.

Advantageously, the arrangement can be made such that for a plurality offilling lines respectively assigned dosing units are combined in adosing block, the input sides of the respective dosing valves beingconnected to a common distributor of the filling material which is undera set buffer pressure.

In such a design, in the dosing block there can be a diaphragm which isassigned to the dosing valves and bypass valves and which is common tothe dosing system as a whole.

In operation with this dosing block, the diaphragm can be triggeredjointly on the bypass valves from a common control line, while for thecontrol sides of the diaphragm on the dosing valves, each filling linehas its own control line for pressure and negative pressure.

The invention is detailed below using one exemplary embodiment shown inthe drawings.

FIG. 1 shows a side view of only the dosing block with the pertinentdistributor of filling material of one exemplary embodiment of thedevice according to the invention, which view is approximately half-sizecompared to a practical embodiment;

FIG. 2 shows a section which has been enlarged compared to FIG. 1according to the cutting line II-II from FIG. 1;

FIG. 3 shows a schematically simplified vertical section of a device forproducing and filling containers, one filling line being shown which isconnected to the pertinent filling line output of the dosing block shownin FIGS. 1 and 2; and

FIGS. 4 a to 4 d show schematic sketches in illustration of theconstruction and manner of operation of the dosing valve means accordingto the exemplary embodiment of the invention.

The invention is explained below using one example in which the devicecontains a plurality of dosing systems, specifically according to FIG.1, fifteen dosing systems 5 which are combined in a common dosing block1. From a common distributor of filling material 3 in which the liquidto be filled in is under a set buffer pressure, each of the dosingsystems 5 within the dosing block 1 receives the liquid filling materialvia a feed line 7, of which only a few are numbered in FIG. 1. In thecourse of operation, the dosing systems 5 deliver the dosing amounts toa corresponding filling line 9 (likewise not all numbered in FIG. 1).Each filling line 9 leads to a device, which is not shown in FIG. 1, forproducing and filling containers, for example, a device according to theknown bottelpack® system.

Of this device, only FIG. 3 schematically shows a production and fillingunit. As is apparent from this figure, each of these systems has afilling mandrel 11 on whose end, which is at the top in the figure,there is a supply head 13 for supply of channels in the filling mandrel11 with media. As FIG. 3 shows, on the supply head 13 the pertinentfilling line 9 is connected to a filling material channel 15 which runscentrally in the filling mandrel 11. The filling material which has beensupplied, dosed by way of the respective filling lines 9, emerges on thelower, fill needle-like end 17 of the filling mandrel 11 for filling ofa respective container 19, which is formed in a forming device 21according to the aforementioned bottelpack® system from plastic tubing23 which is produced by means of an extruder head 25 from plasticizedplastic material.

FIGS. 2 and 4 show details of the dosing units 5 combined in the dosingblock 1. As is apparent, on a flow path 27 which runs between the feedline 7 and filling line 9 two valves are connected in succession,specifically an upstream dosing valve 29 and a bypass valve 31conversely located downstream. Both valves are diaphragm valves with adiaphragm 33 which is pneumatically controlled for deflection andresetting movements. The diaphragm 33, which is preferably made from aplastic material such as PTFE or a rubber material, is common to bothvalves 29 and 31 of a dosing system 5, and also common to all dosingsystems 5 contained in the dosing block 1; i.e., the diaphragm 33extends over the longitudinal area of the dosing block 1. Each dosingvalve 29 has its own pneumatic connection 35 for individual applicationof pressure or negative pressure to the control side 37 on therespective dosing valve 29. In FIG. 1 not all of the pneumaticconnections 35 are numbered. The bypass valves 31 all have a pneumaticconnection 39, which is common to them in order to apply a pressure or anegative pressure to the control side 37 of the diaphragm 33 on therespective bypass valve 21.

FIGS. 4 a to 4 d best illustrate how the dosing systems 5 work. Asshown, on the dosing valve 29 and bypass valve 31 on the control side 37of the diaphragm 33 there is a spherical cap-shaped space 43 into whicha surface region of the diaphragm 33 can be deflected when negativepressure is applied to the control side 37 by way of the pneumaticconnections 35 or 39, by which the opposite closing side 45 of thediaphragm 33 is raised out of the closed position and deflected into therespective space 43; this causes opening of the pertinent valve 29 or31. FIG. 4 a shows the dosing valve 29 in the closed position, while thebypass valve 31 is opened. FIG. 4 b shows the dosing valve 29 open,while the bypass valve 31 is closed. FIG. 4 c shows both valves 29 and31 in the closed position, while FIG. 4 d in turn shows the dosing valve29 closed and the bypass valve 31 open. On the bypass valve 31 there isa respective choke site 41 on the flow path 27. FIG. 4 a shows the restposition of the system prior to the respective dosing process, thedosing valve 29 still being closed while the bypass valve 31 is in theopen position. In this open position of the bypass valve 31 in which thediaphragm 33 is deflected into the spherical cap-shaped space 43, theflow path 27 is significantly widened compared to the state with thebypass valve 31 closed according to the volume of the respective chamber43. With the bypass valve 31 open, passage not only via the choke site41 is thus available to the flow path. FIG. 4 b illustrates the dosingprocess in which the dosing valve 29 is opened, while the bypass valve31 is closed so that the size of the passage of the choke site 41 inconjunction with the time-controlled length of opening of the dosingvalve 29 determines the dosing amount.

FIGS. 4 c and 4 d illustrate the completion of the dosing process byclosing of the dosing valve 29 (FIG. 4 c). After completed closing ofthe dosing valve 29, the bypass valve 31 is opened as shown in FIG. 4 d.The corresponding deflection motion of the diaphragm 33 into thespherical cap-shaped space 43 leads to a considerable widening of theflow path 27 at the bypass valve 31. This lifting motion of thediaphragm 33 with the dosing valve 29 closed produces a suction actionwhich causes return suction of liquid from the downstream filling line9.

As already mentioned, the dosing amount is determined by time control ofthe duration of opening of the respective dosing valve 29 via theindividual pneumatic connection 35. The suction action on the fillinglines 9 can be produced simultaneously for all dosing systems 5 by thepneumatic connection 39 which is common to them being triggered.

It should be noted that for conventional cleaning and sterilizationmeasures as are carried out conventionally before the start of theproduction phases, the dosing valves 29 and the bypass valves 31 arecontrolled into the open position. Thus, the unchoked flow path 27 isavailable for throughflow of cleaning and sterilization media, that isto say, originating from the distributor of filling material 3 via thefeed line 7, dosing system 5, and filling line 9 to the filling materialchannel 15 of the pertinent filling mandrel 11.

1. A device for filling containers, comprising an arrangement (7) forfeeding filling material to at least one dosing system (5) which forms aflow path (27) in which there is a dosing valve (29) which can be openedat least for the duration of the dosing process in order to deliver thedosing amounts of the filling material to the pertinent containers (19)by way of at least one filling line (9), characterized in that thedosing system (5) in the flow path (27) downstream of the dosing valve(29) has a means (31, 33, 43) for optionally producing a suction actionon the flow path (27) and that there is a control mechanism (39) whichactivates the means (31, 33, 43) which produces the suction actiondepending on the dosing processes which have been ended by closing ofthe dosing valve (29).
 2. The device according to claim 1, characterizedin that between the dosing valve (29) and the filling line (9) there isa choke site (41) which constricts the flow path (27) during the dosingprocesses and that in the region of the choke site (41) there is amovable control element (33) which defines the width of the flow path(27) depending on its position setting and which can be transferred intoa position which widens the flow path (27) at the choke site (41) byforming a bypass when the means (31, 33, 43) which produces the suctionaction is activated.
 3. The device according to claim 2, characterizedin that the means which produces the suction action has a bypass valve(31) designed as a diaphragm valve whose diaphragm (33) which forms themovable control element with its one closing side (45) delimits the flowpath (27) at the choke site (41) and to whose other control side (37) anegative pressure can be applied for producing a suction action in orderto cause the diaphragm (33) to execute a deflection motion which widensthe flow path (27) and whose lift produces the suction action on thefilling line (9).
 4. The device according to claim 3, characterized inthat the dosing valve (29) is formed by a diaphragm valve.
 5. The deviceaccording to claim 4, characterized in that the dosing valve (29) anddownstream bypass valve (31) are diaphragm valves which are controlledby a diaphragm (33) extending along the flow path (27) and which iscommon to them.
 6. The device according to claim 5, characterized inthat on the control side (37) of the diaphragm (33) opposite the closingside (45) alternately an overpressure as the closing pressure and anunderpressure as the opening pressure can be applied to the pertinentdosing valve (29) and to the bypass valve (31) via assigned controllines (35, 39).
 7. The device according to claim 6, characterized inthat for a plurality of filling lines (9) respectively assigned dosingsystems (5) are combined in a dosing block (1), the input sides of therespective dosing valves (29) being connected to a common distributor(3) of the filling material which is under a set buffer pressure.
 8. Thedevice according to claim 7, characterized in that in the dosing block(1) there is a diaphragm (33) which is assigned to the dosing valves(29) and bypass valves (31) and which is common to all dosing systems(5).
 9. The device according to claim 8, characterized in that for thecontrol side (37) of the diaphragm (33) on the dosing valves (29) foreach filling line (9) each has its own control lines (35) for pressureand negative pressure.
 10. The device according to claim 9,characterized in that a common line (39) via which a negative pressurecan be applied for simultaneous activation of the respective means whichproduces the suction action is assigned as a control mechanism to thecontrol side (37) of the diaphragm (33) on the bypass valves (31).